Introduction
The distribution of survival times after injury has been described as “trimodal”, but several studies have not confirmed this. The purpose of this study was to clarify the distribution of survival times after injury.
Methods
We defined survival time (ts) as the interval between injury time and declared death time. We constructed histograms for ts <=150 minutes from the 2004-2007 Fatality Analysis Reporting System (FARS, for traffic crashes) and National Violent Death Reporting System (NVDRS, for homicides). We estimated statistical models in which death times known only within intervals were treated as interval-censored. For confirmation, we also obtained EMS response times (tr), prehospital times (tp), and hospital times (th) for decedents in the 2008 National Trauma Data Bank (NTDB) with ts=tp+th<=150. We approximated times until circulatory arrest (tx) as tr for patients pulseless at the injury scene, tp for other patients pulseless at hospital admission, and ts for the rest; for any declared ts, we calculated mean tx / ts. We used this ratio to estimate tx for hospital deaths in FARS or NVDRS, and provide independent support for using interval-censored methods.
Results
FARS and NVDRS deaths were most frequent in the first few minutes. Both showed a second peak at 35-40 minutes after injury, corresponding to peaks in hospital deaths. Third peaks were not present. Estimated tx in FARS and NVDRS did not show second peaks, and were similar to estimates treating some death times as interval-censored.
Conclusions
Increases in frequency of survival times at 35-40 minutes are primarily artifacts created because declaration of death in hospitals is delayed until completing resuscitative attempts. By avoiding these artifacts, interval censoring methods are useful for analysis of injury survival times.
Cocaethylene (the ethyl ester of benzoylecgonine) is a product of the interaction between ethanol and cocaine. The results of preclinical studies and of a pilot clinical study have shown cocaethylene to produce pharmacologic effects similar to those of cocaine. However, no information is available concerning the potency and pharmacokinetics of cocaethylene in comparison to those of cocaine in humans. We report the results of a single-blind, crossover study in which six male, healthy, paid volunteers, who were moderate users of cocaine, were intravenously injected with the water soluble fumarate salt of cocaethylene (0.25 mg/kg cocaethylene base) or an equivalent dose of the water soluble hydrochloride salt of cocaine (0.25 mg/kg cocaine base). Each dose was dissolved in normal saline and injected over a 1-min interval. Test sessions were separated by a 1-week interval. The variables measured were: cocaine and cocaethylene plasma concentrations, subjective and cardiovascular effects. The results indicate, that in comparison to cocaine, cocaethylene had a significant smaller elimination rate constant (0.42 versus 0.67 l/h), had a longer elimination half-life (1.68 versus 1.07 h), and induced ratings of "high" and changes in heart rate that were of lower magnitude (65%, and 43%, respectively). During the period of time that pharmacologic effects were present the plasma concentrations of cocaine and cocaethylene were statistically indistinguishable. This finding supports the conclusion that in humans cocaethylene is less potent than cocaine.
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